{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://spec.soustack.org/stacks/timed.schema.json",
  "title": "Timed Stack",
  "type": "object",
  "properties": {
    "instructions": {
      "type": "array",
      "items": {
        "anyOf": [
          { "$ref": "#/$defs/timedStep" },
          { "$ref": "#/$defs/timedStepSection" }
        ]
      }
    }
  },
  "required": ["instructions"],
  "allOf": [
    { "$ref": "./structured.schema.json" }
  ],
  "$defs": {
    "timedStep": {
      "allOf": [
        { "$ref": "../defs/entities.schema.json#/$defs/StepBase" },
        {
          "properties": {
            "timing": {
              "allOf": [
                { "$ref": "../defs/entities.schema.json#/$defs/StepBase/properties/timing" },
                { "required": ["activity"], "anyOf": [ { "required": ["duration"] }, { "required": ["completionCue"] } ] }
              ]
            }
          },
          "required": ["id", "timing"]
        }
      ]
    },
    "timedStepSection": {
      "type": "object",
      "properties": {
        "section": { "type": "string" },
        "steps": {
          "type": "array",
          "items": {
            "anyOf": [
              { "$ref": "#/$defs/timedStep" },
              { "$ref": "#/$defs/timedStepSection" }
            ]
          }
        },
        "metadata": { "type": "object", "additionalProperties": true }
      },
      "required": ["section", "steps"],
      "additionalProperties": false,
      "patternProperties": {
        "^x-": { "$ref": "../defs/common.schema.json#/properties/extensionLaneValue" }
      }
    }
  }
}